If you’re a Windows Insider who was hoping to take advantage of that “magic window,” here’s a new heads-up: It just closed. Today, Microsoft unexpectedly moved forward to the next version of Windows 10 and released its first Redstone 3 build to Insiders on the Fast ring.

“Windows 10 Insider Preview Build 16170 for PC has been released to Windows Insiders in the Fast ring,” Microsoft’s Dona Sarkar announced on the Windows Experience blog. “You won’t see many big noticeable changes or new features in new builds just yet. That’s because right now, we’re focused on making some refinements to OneCore and doing some code refactoring and other engineering work that is necessary to make sure OneCore is optimally structured for teams to start checking in code. This also means more bugs and other issues that could be slightly more painful to live with – so check your Windows Insider Program settings!”

As promised, there are no major new features in this build. But a few minor changes worth calling out include:

Error 8024a112 is finally fixed. If you are one of the many people experiencing this issue, good new: It’s fixed.

File Explorer Share. Microsoft has updated the Share icon in the File Explorer ribbon to match its new Share iconography.

Cortana Reminders. Microsoft fixed an issue where Cortana Reminders was displayed as a possible share target when Cortana wasn’t enabled.

Mircast fix. Microsoft fixed an issue where Miracast sessions would disconnect a minute or so after the Connect UI was closed if the connection was a first-time pairing.

High DPI fix. Microsoft fixed a high-DPI issue when System (Enhanced) scaling is enabled. Now, applications that use graphics-accelerated content will display correctly.

Night light fix. Now, when you turn off Night light scheduling in Settings, Night light will turn off immediately.

There are a number of known issues, too. Check out the Microsoft blog post for the details.